Solar antenna array and its fabrication

Abstract

A solar antenna array may comprise an array of antennas that may capture and convert sunlight into electrical power. Methods for constructing the solar antenna array may use a stencil and self aligning semiconductor processing steps to minimize cost. Designs may be optimized for capturing a broad spectrum of visible light and non-polarized light. Testing and disconnecting defective antennas from the array may also be performed.

We claim: 
     
         1 . A solar antenna array configured to convert sunlight into electrical power, comprising:
 uniformly horizontally spaced alternating power and ground lines, with sloped sides, and   carbon nanotube antennas of vertically varying lengths connected between the power and ground lines.   
     
     
         2 . The solar antenna array as in  claim 1 , wherein
 the power and ground lines further comprise a conductive metal.   
     
     
         3 . A solar antenna array as in  claim 2 , wherein the conductive metal comprises at least one of the group consisting of gold, silver, platinum, copper and aluminum. 
     
     
         4 . A solar antenna array as in  claim 2 , wherein one of the power and ground lines further comprise catalytic balls. 
     
     
         5 . A solar antenna array as in  claim 3 , wherein the catalytic balls comprise a magnetic conductive metal coated with an oxide. 
     
     
         6 . The solar antenna array as in  claim 5 , wherein the conductive catalytic balls comprise at least one substance selected from the group consisting of nickel, iron and cobalt. 
     
     
         7 . The solar antenna array as in  claim 1 , wherein the antennas of different lengths are configured to cover at least two regions of the light spectrum. 
     
     
         8 . The solar antenna array as in  claim 1 , wherein the antennas of different lengths are locally aligned in at least two directions. 
     
     
         9 . The solar antenna array as in  claim 8 , wherein the two directions are perpendicular to each other. 
     
     
         10 . A method of constructing a solar antenna array, the method including:
 creating a stencil on a silicon wafer,   depositing layers of metal and insulating polymer on the stencil,   separating the array from the stencil,   growing carbon nanotubes between oppositely charged lines of catalytic balls and metal, and   removing defective carbon nanotubes.   
     
     
         11 . The method as in  claim 10 , wherein creating the stencil includes:
 exposing a pattern of lines in resist coated on the silicon wafer,   performing a first V-groove etch on the pattern of lines to obtain first V-grooves,   coating the first V-grooves with silicon nitride,   removing the silicon nitride from the un-etched surface of the silicon wafer,   performing a second V-groove etch on the un-etched surface to obtain one or more second V-grooves, and   coating the wafer with a second layer of at least one of silicon nitride or silicon carbide.   
     
     
         12 . The method as in  claim 11 , wherein the silicon wafer is a p-doped silicon wafer and the first V-groove etch includes an n-doped diffusion. 
     
     
         13 . The method as in  claim 11 , wherein the coated first and second V-grooves have a common width. 
     
     
         14 . The method as in  claim 10 , wherein depositing layers of metal and insulating polymer includes:
 depositing a conductive metal using low-pressure chemical vapor deposition (LPCVD),   simultaneously are sputtering and oxidizing balls of a catalytic metal, and   depositing an insulating polymer.   
     
     
         15 . The method as in  claim 10 , wherein depositing layers of metal and insulating polymer includes:
 applying a voltages on the n-doped diffusion and the p-doped silicon wafer to reverse-bias the PN diode.   depositing a conductive metal using low-pressure chemical vapor deposition (LPCVD),   simultaneously are sputtering and oxidizing balls of a catalytic metal selectively on one of the first and second V-groves, and   depositing an insulating polymer.   
     
     
         16 . The method as in  claim 10 , wherein growing carbon nanotubes includes:
 applying a negative voltage on the power lines and a positive voltage on the ground lines,   heating the power lines,   filling a chamber containing the solar cells with a hydrocarbon gas, and   continuing the applying a negative voltage and a positive voltage, the heating the power lines, and the filling the chamber until the carbon nanotubes have grown between the power and ground lines.   
     
     
         17 . The method as in  claim 10  wherein depositing layers of metal and insulating polymer includes:
 depositing a conductive metal using low-pressure chemical vapor deposition (LPCVD), and 
 depositing an insulating polymer. 
 
     
     
         18 . The method as in  claim 17 , wherein growing carbon nanotubes includes:
 applying a negative voltage on the power lines and a positive voltage on the ground lines,   selectively depositing charged oxidized catalytic balls on the power lines,   etching oxide from exposed surfaces of the catalytic balls and conductive metal,   heating the power lines,   filling the chamber containing the solar cells with a hydrocarbon gas, and   continuing the etching oxide, the heating the power lines, and the filling the chamber until the carbon nanotubes have grown between the power and ground lines.   
     
     
         19 . The method as in  claim 17 , wherein growing carbon nanotubes includes:
 applying a negative voltage on the power lines and a positive voltage on the ground lines,   selectively depositing charged oxidized catalytic balls on the power lines, heating the power lines,   filling the chamber containing the solar cells with a hydrocarbon gas, and   continuing, the heating the power lines, and the filling the chamber until the carbon nanotubes have grown between the power and ground lines.   
     
     
         20 . The method as in  claim 10 , wherein removing defective carbon nanotubes includes:
 heating the ground lines to anneal the carbon nanotubes to the metal,   flipping over the solar array,   grounding the power and ground lines,   disconnecting one or more loose carbon nanotubes by moving a positively charged source across the array perpendicular to the direction of the power and ground lines, from a side of a line containing the one or more loose carbon nanotubes towards an opposite side of the line, and   removing the resulting one or more disconnected loose carbon nanotubes.